Traumatic brain injury in infants and toddlers, 0-3 years old.

OBJECT
Children 0-3 years old present a completely different neurotraumatic pathology. The growing and the development processes in this age group imply specific anatomical and pathophysiological features of the skull, subarachnoid space, CSF flow, and brain. Most common specific neurotraumatic entities in children 0-3 years old are cephalhematoma, subaponeurotic (subgaleal) hematoma, diastatic skull fracture, grow skull fracture, depressed ('ping-pong') skull fracture, and extradural hematoma.


METHODS
We present our 10 years experience in neuropediatric traumatic brain injuries, between 1999 and 2009, in the First Department of Neurosurgery and Pediatric Intensive Care Unit. Including criteria were children, 0-3 years old, presenting only traumatic brain injury. We excluded patients with politrauma, who require a different management.


RESULTS
We present the incidence of these specific head injuries, clinical and imagistic features, treatment, and outcome. We found 72 children with diastatic skull fracture, 61 cases with depressed ('ping-pong') skull fracture, 22 cases with grow skull fracture, 11 children harboring intrusive skull fracture, 58 cephalhematomas, 26 extradural hematomas, and 7 children with severe brain injury and major posttraumatic diffuse ischemia ('black-brain'). Usually, infants and toddlers present with seizures, pallor, and rapid loss of consciousness. First choice examination, in all children was cerebral CT-scan, and for follow-up, we performed cerebral MRI. We emphasize on the importance of seizure prevention in this age group. Children presenting with extensive diffuse ischemia ('black-brain') had a poor outcome, death occurring in all 7 cases.


CONCLUSION
Children 0-3 years old, present with a total distinctive pathology than adults. Children with head injury must be addressed to a pediatric department of neurosurgery and pediatric intensive care unit. Prophylaxis pays the most important role in improving the outcome.


Introduction
Traumatic brain injury (TBI) is the leading cause of death and disability in children. Statistical analyses shows that almost half of patients with a TBI each year in the United Kingdom are children under 16 years, and approximately one third of the patients with cranial trauma per year in the United States are children aged between 0 and 14 years old [1,2].
The most common causes of TBI in children: falls, child abuse, motor vehicle accidents sport accidents, assaults, and instrumental delivery. Regarding age distribution of TBI, there are two risk groups: the first group aged between 0 and 4 years old, and the second 15-19 years old. Boys seem to be affected twice the rate of girls [1].
Traumatic pathology during the first 3 years of life is completely different when compared with adults. Raimondi emphasized the differentials between children and adults' pathology: "children are not young adults" [3].
Specific pediatric scales, adapted according to age, must be used to correctly grade the severity of TBI in children. The most common neurotrauma pediatric scales are: Pediatric Coma Scale/Children Coma Scale (PCS) [4], Children's Coma Score (CCS) [5], Trauma Infant Neurological Score (TINS) [6], and Glasgow Coma Scale (GCS) [7]. The outcome is graded by using neurotrauma pediatric outcome scales, such as: KOSCHI (King's Outcome Scale for Childhood Head Injury) score [8],

Traumatic brain injuries
There were 411 posttraumatic lesions in 312 children.
CPH, which does not spontaneously withdraw under conservatory treatment, requires surgical treatment. In persistent fluid, the hemorrhagic collection is evacuated by tapping (punctioning with a thick needle). In calcified CHP, surgery is performed for cosmetic reasons. A wide, arcuate skin incision in "horse shoe", into the parietal area, on the border of CPH is performed. After a large scalp dissection, the calcified CHP is exposed. We perform a systematic resection of the calcified collection, with continuous wax hemostasis. For good cosmetic effects, level-adjustment of the parietal region is mandatory. No external drainage is needed.

Skull fractures
Linear skull fractures were found in 124 children (39.74%). All children presenting in the emergency room with head trauma, and linear skull fracture on CT-scan or

Skull fractures
Depressed skull fracture may occur following difficult labor, but these patients were not included in our study.
Linear skull fractures in children 0-3 years old are common, but usually have no clinical significance and require no specific treatment. Children with linear skull fracture must be admitted and followed up in a Department of Pediatric Neurosurgery for extradural hematoma occurrence. Diastatic skull fractures carry a high risk of transforming into a growing skull fracture (GSF) in this age group.
Depressed skull fractures may be closed (simple fracture) or open (compound fracture). Depressed skull fractures, with or without focal neurological deficits or seizures, require surgical elevation, according to the depth of deformity. The "Ping-pong" fracture is a particular type of depressed fracture found in newborns. It is usually encountered in parietal bone, and requires surgery.
The depressed fracture, closed or compound, situated over the superior sagittal sinus (SSS) requires an angiography with venous phase or a CT-scan with coronal and sagittal reconstruction, in order to evaluate the size, shape and patency of the sinus beneath the impacted bone. Repairing of SSS must be performed rapidly, in order not to lose blood (in children there is a bigger risk of developing hemorrhagic shock).
A compound fracture, with depressed bony fragments and dural laceration needs emergency surgery. CT-scan can reveal associated hematomas, which require surgical evacuation. Brain laceration carries the risk of subsequent epilepsy, and must be resected. If bone fragments could not be replaced, cranioplasty with methylmethacrylate can be performed within 6 months after initial surgery. We recommend cranioplasty only in children older than 3 years.
Growing skull fracture The grow skull fracture (GSF), is a rare complication of the skull fracture, mainly encountered during infancy and early childhood, in children under three years old [11][12][13][14]. The incidence of GCS is of 0.05 to 1.6% of all skull fractures during childhood [12,13,15,16].
It is a progressive enlargement of diastatic fracture, along with leptomeningeal cyst and brain hernia.
The period of time between head injury and GSF diagnosis can go up to many years [25,26]. Usually, GSF develop within 3-4 months following TBI. Positive diagnosis is made on history of head trauma, followed by progressive enlargement of skull fracture and leptomeningeal cyst protruding through the bone defect.
Factors contributing to GSF occurrence are rapid brain growth and brain pulsation, found in young infants and children [27].
Pathogenesis consists of three phases. Within the first phase, following TBI, a linear skull fracture with periosteum tear and dural laceration occurs. Then, in time, fracture healing is hindered by intracranial hypertension and constant pulsation of the CSF, which favors invagination and entrapment of arachnoids into the diastatic fracture. During the third phase, patients present important bone diastasis, dural defect, progressive leptomeningeal and brain herniation through the diastatic fracture preventing apposition of bone, and elevated intracranial pressure [28]. In time, cerebroventricular changes occur, such as reactive gliosis into the underlying brain, with a subsequent development of porencephalic cavity [13,18,25,29].
During the first phase, patients have bone diastasis and seizures, the second phase presents with bone diastasis, seizures and motor deficits and the last phase with large bone diastasis, focal neurological signs and intracranial hyperpressure.
Skull X-ray, cerebral CT-scan, with bone window and 3D reconstruction reveal the diastatic fracture and leptomeningeal and brain herniation.
Surgery is always required in patients with GCS to prevent seizures and neurological deficits occurrence. The key step is tight closure of dura mater. When dura mater is lacerated and cannot be sutured, the lacerated dura is resected, and duraplasty with periosteum, free flap or pediculated or artificial dura is performed. We recommend dural closure with free flap periosteum, sutured watertight to the normal dura mater, because it is an autologous tissue and it is the most convenient dural substitute. Watertight dural closure is mandatory to avoid GSF recurrence or CSF leakage occurrence [14].
Usually, dural tear extends beyond the fracture borders, that is way the fracture should be extended to craniectomy, until normal dura is reveled [15,27,30,31]. In many cases, dural tears may involve transverse or sagittal sinus [23]. In such cases bleeding from the dural sinus can occur, that is life threatening in these age groups. Even if the sinus is not torn, its vicinity may pose problems regarding dural repair. If the fracture is parallel to the sinus, dural repair is difficult, because of the narrowness of the dural edge to the venous sinus. If proximity of the sinus does not allow graft suture with borders of normal dura mater, the graft can be sutured with dura across the sinus after extending the craniectomy or directly to the skull's edge above the sinus. If the fracture is perpendicularly to the sinus, the end closest to the venous sinus does not need repairing. We extended the fracture to a right frontoparietal craniectomy over the coronal suture, reaching up to the anterior fontanelle and suturing a patch of periosteum to free dural borders.

© 2011, Carol Davila University Foundation
We do not recommend cranioplasty in children under 3 years old, because a child's head is growing, and there is a high risk of bone graft displacement [14]. Plus, new bone apposition within the skull defect occurs in most children and in infants dura mater has osteogenic potential [32][33][34][35]. Cranioplasty with methylmethacrylate was reported to have good results on long-term follow-up [13].
CSF shunt diversion is indicated in CSF leakage in patients with adequate treatment of GSF and concomitant hydrocephalus.
Finding the group of patients carrying risk of developing GSF immediately after trauma is challenging. To develop a GSF, the diastatic fracture and dural tear are mandatory. The age 0-3 years old is a predisposed factor for GSF. Cranial X-rays and cerebral CT-scan cannot show dural tears [12,18,22,23]. Cerebral MRI can indent dural tears, and has a high predictive value of developing GSF, but, unfortunately, we, like many other neurosurgical departments, do not have an MRI in emergency. Ultrasonography through diastatic fracture line can identify dural tears [12,19].

Skull base fractures
Patients with skull base fractures present some characteristic signs, such as periobitar ("raccoon's eyes") or postauricular ecchymosis (Battle's sign), epistaxis, otorhagia, etc. The diagnostic of skull base fracture is made on CT-scan. The consequence of skull fractures is CSF leakage, with rhinoliquorea or otoliquorea. In young children, 0-5 years old frontobasal fractures are common [36].
Surgery is required in persistent CSF leakage, with lack of response to conservative therapy (lumbar punction, or lumbar drainage). Closing the dural tear, and if possible bone defect is the key step in surgery. Several approaches can be achieved: classical, transcranial extraor intradural, or transnasal transsfenoidal endoscopic in CSF leakage with rhinoliquorea, difficult in children. Defects within the cribriform plate, planum sphenoidale, superomedial surface of the orbit, and the posterior surface of the petrous bone, may be closed through either intradural or extradural approaches. Intradural approaches are fit for defects into the sphenoidal wing, or tip of the petrous bone [37]. Indirect transnasal transsfenoidal endoscopic approach consists of packing the sphenoidal sinus with fat tissue, muscle, and a bone [37]. In many cases, a multidisciplinary team (neurosurgeon, ophthalmologist, oromaxilofacial surgeon) is needed for dural and craniofacial skeleton repairing [36].

Penetrating head injury (PHI)/Craniocerebral wounds in children
PHI are rare in children [38]. In PHI, all anatomic structures, scalp, skull, dura mater, leptomeningeal layer and brain parenchyma are involved. Many bizarre injuries were reported, caused by pencils, keys, power drills, glasses, chopsticks, animal claws and iron bars [38].
According to the nature of the traumatic agent, two categories of craniocerebral wounds are distinguished: gunshots craniocerebral wounds and craniocerebral wounds produced by different agents other than gunshots.
Generally, gunshots craniocerebral wounds are encountered in children during war area. Local exam shows traumatic mark and neurological exam evaluates the level of consciousness, focal neurological syndrome, and meningeal syndrome.
Classical skull X-ray and CT-scan, showing the extent of the lesion and the presence of associated injury, complete the diagnosis.
Urgent surgical treatment is mandatory, and its purpose is to remove the bone fragments, and cerebral detritus, reconstruction of anatomical layers, and antibiotherapy.

Extradural hematoma (EDH)
EDH is a posttraumatic intracranial blood collection between the inner table of the skull and dura mater.
EHD may be:  Convexital EDH; located supratentorially or cerebellarly; the source of bleeding is usually arterial, from the meningeal middle artery, fracture line, diastatic fracture (diploic veins).  Suprasinusal EDH; located over the superior sagittal or transverse sinus; the source of bleeding is usually venous. EDH is usually unilateral, it is most commonly encountered into the temporoparietal region, followed by frontal and occipital regions, and it is rare in vertex and posterior fossa. Acute EDHs in pediatric population are rare, with a frequency of occurrence around 3% of all TBI. In children under 3 years old, EDH is uncommon, because dura mater is adherent to the inner table.
Children with EDH may present immediate posttraumatic or delayed loss of consciousness, focal neurological deficits, intracranial hypertension, and progressive worsening in cerebral herniation. Clinics depend on the source of bleeding, which assert the rapidity of progression (supraacute, acute, subacute hematoma), location and presence of associated lesions. In infants, a large amount of blood can accumulate into the extradural space, leading to large EDHs, due to the opened fontanelle and easily separating sutures. Up to 100 cm 3 of blood can collect in the extradural before any neurologic signs occur. Total blood volume in children is of 550-600 ml at the age of 3 months, 700-800 ml at 1 year, 850-950 ml at 2 years, 1300-1400 ml at 5 years and 3500-4000 ml at 15 years. So, infants with EDH may present with acute anemia, hypotension, and hypovolemic shock.
Clinical features may be:  brief posttraumatic LOC, followed by lucid interval for several hours, and then progressive alteration of the level of consciousness  persistent posttraumatic coma  posttraumatic coma, followed by the regaining of consciousness  posttraumatic conservation of consciousness without coma  posttraumatic conservation of consciousness with delayed coma Clinics in newborns and infants are vague consisting of hypothonia, seizures, and tense fontanelle.
EDH in children with hydrocephalus and ventricular shunt is a serious and urgent chapter of children pathology. In such children, CT is mandatory immediately. Even after a mild TBI usually initially asymptomatic, coma may rapidly onset. CT-scan must be performed without delay [39]. Usually, there is no lucid period, rapid alteration of level of consciousness immediately after trauma and severe impairment of vegetative functions. The supratentorial EDH patients present with motor deficits, jacksonian seizures, anisocoria, and comatose state [40].
Posterior fossa EDH occurs less frequently than supratentorial ones, but it is the most common posttraumatic space-occupying lesion of the posterior fossa in children [41]. Posterior fossa EDH blocks cistern magna, causing brainstem compression and obstructive hydrocephalus with acute intracranial hypertension. Children with EDH posterior fossa may have a rapid deterioration without significant warning symptoms and may result in death.
The positive diagnosis, location and size of EDH are made on CT-scan. EDHs are extraaxial lenticularshaped masses situated between the dura and the inner table of the skull, with density varying according to the age of the lesion. A normal CT-scan immediately after trauma, does not exclude the possibility of further development of an EDH.
Children with skull fractures, presenting with vomiting or alteration of the level of consciousness, must be clinically observed together with a CT-scan for the development of an EDH.
Surgery Surgery consists of the hematoma evacuation. One of the most important therapeutic targets is blood replacement in the shocked child, which should be done within 20-30 minutes, before starting the operation.
Conservative treatment can be attempted in an alert child, with no focal neurological deficits, in which CTscan showed an EDH having a volume < 25 ml, with a thickness < 10 mm and midline shift < 4 mm. The child must be held in a neurosurgical center, where surgery can be performed if needed, under attentive clinical observation and CT-scan must be repeated [42].

Diffuse brain swelling (DBS)
Diffuse brain swelling in newborns is due to birth asphyxia and secondary reperfusion. DBS is mixed by vasogenic and cytotoxic edema.
The diagnosis is established by CT-scan and the treatment is specific, according to the clinical status. The particularity of DBS in children is represented by its early onset. It is very severe and it is often followed by diffuse cerebral ischemia ("black brain").
Posttraumatic DBS can accompany any cerebral lesion in children and it requires intracranial pressure (ICP) monitoring. After failure of conservative therapy, bilateral decompressive craniectomy may be needed as the last resort treatment strategy. In children, decompressive craniectomy improves the neurological outcome and diminishes death risk [43,44]. The necessity of decompressive craniectomy and duraplasty is especially important in children, due to the lack of response to usual therapies, in the treatment of intracranial hypertension [45,46].
The surgical technique for diffuse brain swelling: wide bilateral hemicraniectomy, dural opening in a stellate fashion, dural graft to increase the available volume before closure, and finally wound closure.

Conclusions
Neurotrauma pathology is very different in infants and toddlers compared to different age patients. Accurate and rapid clinical and neuroimagistic diagnosis is the key of success. The Pediatric Neurosurgical Department and Pediatric Intensive Care Unit represent a vital necessity. Long time follow-up is mandatory.
CT-scan is the main investigation tool and must be performed in all children with TBI, in the first three hours.
Hemorrhagic shock may rapidly occur in infants and young children.
Grow skull fracture is a specific posttraumatic lesion in infants and young children. Surgery is always required to prevent neurological deficits and/or seizures occurrence.
Tight dural closure is the key step in surgical management. Duraplasty can be done with a patch of pericranium / periosteum. Cranioplasty is not indicated in infants.